Embodiments herein generally relate to electrostatographic printers and copiers or reproduction machines, and more particularly, concerns a sheet registration unit that moves relative to the media path (translates) in a direction perpendicular to the media path direction as the media width changes to center the media alignment unit with respect to the media sheets.
To handle different media widths, conventional registrations systems sometimes utilize two, three, or more nips that are selectively opened and closed to accommodate different paper widths. For example, U.S. Patent 2004/0065994 (the complete disclosure of which is incorporated herein by reference) discusses common multi-nip registration systems. While many registration systems use two nips, some products that are directed to large sheets use three or more nips to reduce the loads when large sheets are registered. The embodiments described herein are useful with edge registered systems (where one edge of the media sheets is always at the same location, regardless of width of the media sheets) because, in such systems, the center line varies from the edge as the sheet width changes. In a center registered system the sheet is centered to the registration system (unless the upstream subsystems are edge registered).
Thus, some current printer devices use nip registration systems that can have two, three, or more nips. The three nips provide different nip stance offsets depending on the paper cross process size. Specifically, the two outside nips are used for the large sheets and one outside nip and the center nip together are used for the small sheets.
Embodiments herein provide an apparatus that includes a controller and a media path operatively connected to the controller. The media path feeds media sheets in a media path direction from a media source (e.g., paper tray) to a destination (e.g., a marking device placing marking on the media sheets).
A media alignment unit (registration unit) is positioned along the media path and is operatively connected to the controller. In some embodiments, the media alignment unit can comprise only two nips. In media alignments units, the nips operate at different speeds to align the sheet width edges of the media sheets to be parallel to the media path direction as the media sheets travel along the media path. A sheet width sensor can be operatively connected to the controller. Such a sheet width sensor determines the distance between the sheet width edges of the media sheets and the lateral position of the sheets.
Embodiments herein include movable supports that are connected to the media alignment unit. The movable supports are also operatively connected to the controller. The movable supports comprise actuators that operatively connect to the controller and the actuators are controlled by the controller.
The movable supports move the media alignment unit relative to the media path in a direction perpendicular to the media path direction under control of the controller. This movement centers the media alignment unit with respect to the media sheets. Therefore, the movable supports position the media alignment unit at a location equidistant from the sheet width edges of the media sheets. Thus, the movable supports move the media alignment unit so as to center the media alignment unit along a centerline of the media sheets. The centerline is positioned equidistant between the sheet width edges of the media sheets. Further, the movable supports move the media alignment unit to different positions depending upon the distance between the sheet width edges for different width media sheets and the lateral position of the sheets on the media path.
Stated in terms of a method, the embodiments herein feed media sheets along a media path within an apparatus in a media path direction from a media source to a destination and align the media sheets as the media sheets travel along the media path using a media alignment unit. The embodiments move the media alignment unit in a direction perpendicular to the media path direction using movable supports to position the media alignment unit at a location equidistant from sheet width edges of the media sheets.
As mentioned above, the movable supports can comprise actuators and the moving of the media alignment unit comprises operating such actuators. The moving of the media alignment unit is performed so as to center the media alignment unit along the centerline of the media sheets. The moving of the media alignment unit moves the media alignment unit to different positions depending upon the distance between the sheet width edges for different width media sheets. Once the media sheets are moved to the marking device, the method can place marking on the media sheets using the marking device.
These and other features are described in, or are apparent from, the following detailed description.